Theoretical Maximum Habitat Inputs

Habitat inputs for Reorienting to Recovery theoretical maximum habitat model run was scaled existing habitat to area curves using the 2018/2019 BiOp flows.

Fall Run Habitat

Spring Run Habitat

Winter Run Habitat

Non Run Specific Habitat

For each river reach in the SIT DSM, the theoretical maximum habitat was calculated for above and below dams and for unregulated rivers. See methodology for overview of theoretical maximum habitat modeling approach.

Theoretical maximum habitat was not calculated at specific flows and therefore to combine this new habitat with existing, the existing habitat to area curves were scaled using the following approach.

1) Calculate flow point of reference

For in-channel habitat we use the median flow over the entire modeled period 1980 - 2000. Flow inputs come from CalSim II benchmark from the 2019 Itp and 2020 BiOp. For floodplain habitat, we use a 2 year flow value, which represents a flow that is exceeded in 50% of the years between 1980 and 2000. This is done by take the yearly rolling maximum of monthly CalSim flows and applying a cumulative distribution function on the ranked values to find the proportion of all values less than or equal to the ranked order. An interpolation function is then developed to to find the 2 year flow value.

2) Calculate the proportion increase of habitat at flow point of reference

The proportion increase between baseline and theoretical maximum habitat was calculated using the following equation. The existing_acres were calculated using the median (for in-channel) and 2-year flows (for floodplain).

proportion_increase = (max_hab_acres - existing_acres) / existing_acres + 1

3) Scale existing habitat by proportion increase

The existing acres are then scaled for each watershed (ws) by the calculated proportion_increase.

new_hab_acres <- DSMhabitat::fr_fp$biop_itp_2018_2019[ws , , ] * proportion_increase

4) Save new data objects for Theoretical Maximum Habitat

The new data objects are saved in the package as:

Fall Run

DSMhabitat::fr_spawn$r_to_r_tmh

DSMhabitat::fr_juv$r_to_r_tmh

DSMhabitat::fr_fry$r_to_r_tmh

DSMhabitat::fr_fp$r_to_r_tmh

Spring Run

DSMhabitat::sr_spawn$r_to_r_tmh

DSMhabitat::sr_juv$r_to_r_tmh

DSMhabitat::sr_fry$r_to_r_tmh

DSMhabitat::sr_fp$r_to_r_tmh

Winter Run

DSMhabitat::wr_spawn$r_to_r_tmh

DSMhabitat::wr_juv$r_to_r_tmh

DSMhabitat::wr_fry$r_to_r_tmh

DSMhabitat::wr_fp$r_to_r_tmh

Non Run Specific Habitat

DSMhabitat::delta_habitat$r_to_r_tmh See Calculating Theoretical Maximum Habitat for details on Delta methodology for theoretical maximum habitat

Comparison plots between Baseline and Theoretical Maximum Habitat

Spawning Habitat:
Fall Run:

Winter Run:

Spring Run:

Inchannel Juvenile Rearing Habitat:
Fall Run:

Winter Run:

Spring Run:

Floodplain Rearing Habitat:
Fall Run:

Winter Run:

Spring Run:

Delta Habitat